The invention relates to self-retaining means for fasteners particularly to screws.
Up to now, the only possibility to make sure that a fastener remains in a plate is to secure it with a relatively thick element, or to apply such type of screws wherein a neck part is below the head of the screw and the neck part is longer than the thickness of the plate wherein upon introducing the screw into a bore of the plate, the axis of the screw generally moves out from the geometrical axis of the bore, which hinders separation of the screw.
There is, however, still a real danger that the geometrical axis of the bore and that of the screw coincide and such a position, even if only for a short time, permits the screw to drop out, which is always undesirable but it is even dangerous in the field of surgery.